Methods of forming a graphene material on a surface are presented. A metal material is disposed on a material substrate or material layer and is infused with carbon, for example, by exposing the metal to a carbon-containing vapor. The carbon-containing metal material is annealed to cause graphene to precipitate onto the bottom of the metal material to form a graphene layer between the metal material and the material substrate/material layer and also onto the top and/or sides of the metal material. Graphene material is removed from the top and sides of the metal material and then the metal material is removed, leaving only the graphene layer that was formed on the bottom of the metal material. In some cases graphene material that formed on one or more side of the sides of the metal material is not removed so that a vertical graphene material layer is formed.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method for forming graphene material on a surface, comprising the steps of: forming a material substrate; depositing a metal material layer on the material substrate, the metal material layer being a patterned metal material layer having at least one side surface and having a bottom surface in contact with the material substrate and further having a top surface not in contact with the material substrate; forming a desired concentration of carbon in the metal material layer to form a carbon-containing metal material; applying a heating/cooling cycle to the carbon-containing metal material layer to diffuse the carbon within the metal material layer; cooling the carbon-containing metal material layer to precipitate a first graphene material (GM) onto the bottom surface of the metal material layer and further to precipitate a second graphene material (GM2) onto the top surface of the metal material layer and onto the least one side surface of the patterned metal material layer; removing GM2 from the top surface of the metal material layer; and removing the metal material layer without removing the GM; wherein the GM remains on the surface of the material substrate; and wherein the GM2 is not removed from the at least one side of the metal material layer, the GM2 that is not removed comprising a vertical grapheme material structure.
2. The method according to claim 1 , wherein the material substrate is selected from the group consisting of silicon, sapphire, silicon-on-insulator, quartz, gallium arsenide, gallium nitride, indium phosphide, and cadmium telluride.
3. The method according to claim 1 , wherein the metal material is selected based on one of a solubility limit of carbon in the metal material and a diffusion characteristic of carbon in the metal material.
4. The method according to claim 1 , wherein the metal material comprises one of copper, nickel, ruthenium, cobalt, iron, and zinc.
5. The method according to claim 1 , wherein the metal material comprises a carbon alloy.
6. The method according to claim 1 , wherein the metal material layer is a nanoparticle metal material layer.
7. The method according to claim 1 , wherein the concentration of carbon in the metal material layer is formed by exposing the metal material to a carbon-containing vapor at a selected temperature.
8. The method according to claim 1 , wherein the concentration of carbon in the metal material is formed by depositing a layer of carbon or carbon-containing material on the top surface of the metal material layer.
9. The method according to claim 1 , wherein the concentration of carbon in the metal material is formed by ion implantation of carbon or carbon-containing atoms into the metal material.
10. The method according to claim 1 , wherein the heating/cooling cycle is a rapid thermal anneal.
11. The method according to claim 1 , further comprising depositing a material layer on a top surface of the material substrate before deposition of the metal material.
12. The method according to claim 11 , wherein the material layer comprises one of aluminum oxide, boron nitride, silicon nitride, silicon oxide, hafnium oxide, aluminum nitride, aluminum gallium nitride, gallium nitride, aluminum gallium arsenide, indium gallium arsenide, cadmium telluride, organic light emitting diode material, material as substrate for touch screen, thin film of photovoltaic material, thin film of material for display, barrier metal, and titanium nitride.
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April 6, 2012
August 6, 2013
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